Antimanipulative combination lock



Oct. 16, 1956 c. M. HIRN 2,766,608

ANTIMANIPULATIVE COMBINATION LOCK Original Filed April 23. 1952 ATTYs ANTIMANIPULATIVE COMBINATION LOCK Charles M. Hirn, incinnati, Ohio, assignor to The Mosler Lock Company, Covington, Ky.

Original application April 23, 1952, Serial No. 283,901. Divided and this application November 10, 1955, Serial No. 546,097

3 Claims. (Cl. 70-303) The familiar known and used combination locks of several types and numerous makes are allegedly insecure against surreptitious opening by certain skilled persons who, in the absence of a knowledge of the combination by means of which the lock is to be opened, reputedly form the combination in a given lock with only the aid of the sound and feel of the mechanism while operating the usual dial knob of the lock.

It is the major object of the present invention to render the aforesaid lock structures antimanipulative by such alleged persons and practices without expensive or elaborate redesigning of the existing lock structures.

This application is a division of my copending United States patent application Serial No. 283,901, filed April 23, 1952.

A further object of the invention is to accomplish the aforesaid purpose essentially by a mere reversal of the spring member of the lock which operates on the tense so that the latter is constantly urged away from the notched tumbler series of the lock and to provide simple and inexpensive arrangement of the lock parts which make it impossible to maintain a manual control of the tumblers and the lock operating cam in such a simultaneous manner as would aiford an intelligible external sound or feel that could indicate the position of the tumbler notches interiorly of the lock.

Another object of the invention is to provide in the various types of combination locks a simple arrangement of the existing parts wherein the bolt or slide is constantly biased to locking position and the fence means is constantly urged out of contact with the tumblers.

These and other important objects are attained by the means described herein and exemplified in the accompanying drawings in which:

Fig. 1 is a fragmental elevational view of a door carrying a combination lock embodying the invention, the casing cover and associated tumblers being removed to show the interior of the lock casing with its associated parts in locked position.

Fig. 2 is a cross sectional view through the door and the completely assembled lock looking in the direction of the arrows 22 in Fig. 1.

Fig. 3 is a cross sectional view through the assembled lock, looking in the direction of the arrows 33 in Fig. 1.

it has been proposed to remedy the alleged insecurity of conventional combination locks by the use of attachments that extend through the lock casing to the exterior thereof but such arrangement leave much to be desired ecause locks so constructed may be required to be mounted on structures where space is too limited or where the attachment may be subject to surreptitious tampering while the structure is unlocked and open.

By the means of the present invention these and other objections are avoided, and compact and efircient antimanipulative locks are provided.

In order that the simplicity and low cost of producing the improved antimanipulative locks of the present inven- S ttes Patent tion may be more readily understood, it should be observed that most of the parts of the corresponding type of prior known familiar lock may be adapted and utilized unchanged in the improved lock while simple and inexpensive changes are made in the remaining few parts. It is thus possible to convert existing old locks in stock or in use in minimum of time and with a minimum of modified parts if desired.

Reference is now made to the drawing wherein the invention is embodied in a familiar type of combination lock in order to render it antimanipulative. In this embodiment a door 36 for a cabinet or vault would be provided at two or more of its edges with sliding bolts (not shown) adapted to enter corresponding recesses in the door frame in known manner, said bolts being connected to the outer ends of rec-iprocable bolt operating bars or rods 3'7. The bars 37 may be operatively connected with an operating cam plate 38 by entering .angularly turned lugs 39 on the plate through perforations 40 in the adjacent ends of the several bars 37. The cam plate 38 is fixed for rotation with a stud 40 which is journaled in the door and has an externally disposed handle -41 thereon connectible and disconnectible with the stud in known manner by means of a key controlled lock 42. The ability to exert 'rotative force on the stud 40 is thus dependent on operation of lock 42. The cam plate 38 has a cam nose 43 having a fiat edge.

Mounted on door 36 in laterally spaced relation to the aforesaid cam plate 38 is a combination lock 44 of a generally familiar type for controlling rotary movement of the aforesaid cam plate 38, said combination lock having the invention embodied therein to render it antimanipulative. The side wall 45 of casing 46 of lock 44 is disposed so as to clear the rounded shoulder 47 when the cam plate 38 is turned counter-clockwise as viewed in Fig. 1. A slide plate 48 is reciprocably mounted in the casing 46 and has a sturdy end '49 guidely reciprocable in an aperture in casing wall 45 and normally projecting, as shown in Fig. 1 to present a corner edge 50 to the flat edge 43 on cam plate 33 in a manner such that the member 4349 is shifted into the casing 45 and member 49 is retained practically in the plane of the casing wall 45 by the rounded shoulder 47. The slide plate 48 has an upright extension or lug 51 which may enter a notch 52 in the driver disc 53 of the lock 44 when said notch is properly positioned as shown in Fig. 1

"to receive the said extension 51, and the slide plate 48 is not otherwise restrained against movement.

The lock 44 has a fence member 54 adapted for hinged or swinging movement on a pin 55 so that the free edge 56 may enter the aligned notches (not detailed) in the tumbler discs 57 shown fragmentally in Fig. 2, the tumblers being of selected known construction as previously described and rotatably supported on the inside of easing cover 58. The usual driver lug 59 is constantly engaged with the tumbler 57 adjacent the driver disc '53 and the latter is rotatable to set up the tumbler combination by known or conventional arrangement of the arbor 60, and the dial knob 61 and the dial 62 that cooperates in the usual manner with an index mark on the dial ring 63 fixed 011 the exterior face of the door 36. When the tumbler combination is properly set up the tumbler notches are aligned on centers that coincide with a radial plane that is at an angle to a radial plane passing through the axis of the driver disc and the center of extension 51. The fence 54 may then be moved about its pivot 55 to enter the tumbler notches but only if the driver 53 has. been adjusted so that the driver notch '52 is in position to receive the extension 51.

has its free edge 56 spaced from the peripheries of the tumbler discs 57, in other Words the fence is biased by its spring in a direction opposite to that in common and prior known combination locks of all types.

The fence spring 64 thus forces the fence away from the tumblers and against a pin or screw stud abutment 65 carried by slide plate 48 thus forcing said slide plate outwardly of the casing so that the end 49 assumes the position shown in Fig. 1 wherein the operating cam plate may be used to exert its cam action on the slide plate by means of the handle lever 41. Obviously if the driver disc is not adjusted to the position shown in Fig. 1 manual pressure on handle 41 will impairt only slight movement of slide plate 48 through cam plate 38 whereupon the extension 51 will be blocked against the periphery of disc 53. It is further desirable to provide shallow peripheral notches 66 on the disc 53 to provide a multiplicity of chances for an unauthorized person to force the extension 51 into any one of them by pressure on handle 41 and to thereby gain the false impression that the extension 51 entered notch 52 and that the edge of fence has engaged the periphery of one or several tumblers 57. Under such condition of pressure of cam plate 38 on the end 49 of the slide plate it becomes impossible to manually rotate the driver from the dial knob 61. Moreover by tightening the holding screw 67 to a proper degree an adequate degree of friction is maintained between the cam plate 38 and its spacer 68 which causes the handle 41 to operate rather stifily and to thus frustrate any attempt to employ an alleged delicate sense of touch or feel in gaining information as to the condition of the lock mechanism. This condition also effectively dampens and substantially obliterates lany distinctiveness between sounds produced within the lock when notch 52 is positioned to receive extension 51 and the end 56 of the gate strikes one or more tumbler discs 57 in which the notches are not set up to receive the gate. Under the latter circumstance also the driver cannot be turned in an attempt to manipulate the tumblers Without first turning the handle 41 in the opposite direction and thereby retracting the cam plate 38 and permitting the slide 48 to be projected fully by operation of the spring urged fence 54 on the stud 65 on said slide plate.

The lock is thus amply protected against manipulation by the aid of sound and feel or touch in the absence of a knowledge of the proper combination. If desired the lock may also be protected against violent entry by providing it with any suitable form of so-oalled dynamite latc 69 which is retained inoperative by a pin 70 on the casing cover 58 leaving the slide plate normally free to reciprocate under proper operation of the lock. If the cover 58 is displaced by violence to the lock, a lug 71 on the latch enters an edge notch 72 on the slide plate and renders unlocking movement impossible.

A pair of stop pins 73 serves to limit the rotary movement of the cam plate in opposite directions by means of handle 41.

It will be understood that the invention is not to be considered as limited to embodiment in the specific type of conventional locks indicated herein in order to render it antimanipulative. The disclosure is sufficiently representative of the simple and inexpensive adaptation thereof to other specific locks of these and other types to enable 'the application of the invention to the latter by those skilled in the art within the spirit of the invention and the scope of the appended claims.

It is to be noted special completely new designs of lock of antimanipulative nature are not necessary, but are not to be excluded from the practice of the present invention.

What is claimed is:

1. In an antimanipu'la'tive combination lock, the combination with a door having a manually rotatable bolt operator including a cam, and a shallow lock casing containing a slide plate with a thickened end movable through an opening in the end of the easing into and out of the path of movement of saidcam, of a gated rotary driver disc disposed above the slide plate, a fixed lug on the plate extending to the -level of the top of the driver and movable into the gate when the latter 'is aligned with said lug, r3. fence pivoted in 'the casing alongside said slide with the bottom edge of the fence arranged to move across the top face of the slide to and from .a position over the top face of said driver, a stud in the slide behind said fence, a spring constantly urging the fence outwardly beyond the periphery of the driver and against said stud whereby the slide plate is urged outwardly through the opening in the casing, a cover on the casing, a plurality of notched rotary combination tumbler discs supported by said cover in coaxial cooperative relation with the driver and externally operable means for manually rotating the driver for moving the tumbler discs according to predetermined combination for aligning the tumbler notches in position to receive the fence and positioning the driver gate in position to receive said lug i n=11he slide plate when the thickened end of the latter is subjected to pressure by the bolt operator cam.

2. The combination as set forth in claim 1 characterized by the fact that the driver has a series of peripheral irregularities for binding engagement with the lug on the slide plate when the driver gate is out of alignment with said lug and the slide plate is under the influence of manual pressure exerted on the cam and for positively resisting operation of said driver.

3. The combination as set forth in claim 1 characterized by the fact that the fence is so pivoted with relation to the periphery of the driver that the stud on the slide can move the free end of the fence over the top of said driver and into the path of the tumbler discs only when the lug on the slide plate has entered a substantial distance into the driver gate.

No references cited. 

